Cyber not shutting down from DMX

I would assume since you said you were giving it the DMX shutdown sequence, that you are doing the complex sequence outlined in the manual as to how to reset and shutdown a fixture.

What console are you using?

Yes that's correct, the sequence from the manual.

Using an MA console.

The two other units being maintained responded correctly to the sequence, so the programming works ok.

Check you data path. If you are going through certain types of opto-splitters or have other devices before that fixture in the DMX link it might be getting some sort of signal still that keeps it from shutting down.

Another thing I have seen quite often with Cybers that might cause this is the 14-pin wiring harness between the PSB and Logic cards. Look for burn marks on the connectors and/or damage to the cable inbetween.

What model and date of manufacture is this Cyber?

Hope this helps:)

The data path was only about 2 meters long while the unit was on on the workbench! :) I did however try it with and without a terminator, and also replaced the rs485 transceiver.

The wiring harness was given a cursory look but I'll check it again more closely. Not sure of exact date - reasonably old though.

If it is very old, you also probably want to look at the motor wiring harness (the big bundle that goes out from the logic to all the steppers).

It passes near an opening in the lamp box, and the original harnesses would have the wiring coatings break down due to UV from the lamp over time.....the newer harnesses are teflon coated wires and don't really have this issue. Just look for discoloration of the wires with the logic card removed.

I still have a bunch of fixtures that won't lamp off from a DMX command ... they stop responding to dmx after the command, but never lamp off, until i shut off the opto, in which they will then lamp off, and cool down ... i've replaced / swapped, logics, psb, 14pin harnesses, transformer, ... u name it ... these bastards are stubbern... it's so wierd.

[quote=stephenwyker;34766]...until i shut off the opto, in which they will then lamp off, and cool down....

Sounds like the opto is sending enough to keep the units lit in this case.....otherwise could be the lamp SCRs as posted above.

Hope this helps. :)

[quote=stephenwyker;34766]I still have a bunch of fixtures that won't lamp off from a DMX command ... they stop responding to dmx after the command, but never lamp off, until i shut off the opto, in which they will then lamp off, and cool down ... I've replaced / swapped, logics, psb, 14pin harnesses, transformer, ... u name it ... these bastards are stubborn... it's so wierd.

This ^
Because the opto is still alive some units will continue to run.
Shut down the opto and the lamps will go out. I see this all the time.